Pectin product and process of producing same



Patented June 17, 1924.

UNITED STATES 1,497,884 PATENT OFFICE.

IELOISE J'AMESON AND FRANCIS N. TAYLOR, OF CORONA, AND CLARENCE P. WILSON,

OF POMONA, CALIFORNIA, ASSIGNORS TO CALIFORNIA FRUIT GBAOWERS 'E'X- CHANGE, 01 LOS ANGELES, CALIFORNIA. A CORPORATION OF CALIFORNIA.

PECTIN PRODUCT AND PROCESS OF PRODUCING SAME.

No Drawing.

To all whom it may concern:

Be it known that we, ELOISE JAMnsoN and FnANoIs 'N.-TAY'I.oR, citizens of the United States.- residingat Corona, in the 5 county of Riverside. and CLARENCE P.

WILSON, a citizen of the United States, residing at Pomona, in the county of Los Angeles, and State of California, have invented new and useful Pectin Products and Processes of Producing Same, of which the following is a specification.

This invention relates to a pectin product suitable for use in making jelly and similar, products, and a process for producing tl1e pectin product. 7

Heretofore, the processes employed for producing pectin products have resulted in impure products containing more or less of the vegetable materials naturally associated with the pectin and also more or less of the products resulting from chemical changes in the pectin. Pectin is a material existing naturally in a large number of organic materials such as fruits and vegetables. Pectin, however, is very readily altered and difiicult to extract and purify without causing chemical changes in the pectin which will not only result in an impure pectin product but will result in a pectin product which has a low jellifying power. Pectin maybe considered as octo-methylester of pectinic acid. This pectin may in the-process of extraction hydrolyze or lose one or more of the methyl groups naturally present in the pectin and the resulting pectin while still possessing a jelli fying power will be found to possess this powerin a materially lower degree. As the methyl groups are progressively removed from the pectin. the jellifying power of the same is reduced and may be practically destroyed.

These changes in the pectin may be produced in numerous manners. Thus in the I peel of citrus fruit there exists certain enzymes (called enzyme-pectinase) which if brought in contact with'the pectin act upon the pectin to form decomposition products of the same, finally converting the pectin to pectinic acid. Pectinic acid is not suitable for making jellies and the formation of this pectinic acid not only destroys the useful pectin but dilutes the pectin not destroyed and operates to prevent. the jellying of the pectin product. The pectin is milky liquids in the extract.

Application filed August 22, 1923. Serial No. 658,706.

likewise deteriorated by heating to high temperatures such as over 100 centigraole and this deterioration may occur at any time in the process where this high temperature is exceeded. The pectin may also be destroyed by the action of strong alkali which converts the pectin to pectinic acid salts or by the action of strong or oxidizing acids. Moreover, there are associated with the pectin in the natural state certain materials which when the pectin is extracted are normally suspended in the extract or form Thepectin normally produced from such an extract will produce a cloudy jelly. .This will not occur if these suspended solids and milky liquids are removed, as a pure pectin product will produce a brilliant and clear jelly.

An object. of this invention is to provide' a pectin product which will be substantially .free from undesirable suspended solids and substances forming milky liquids when in solution with the pectin so that the pectin may produce a brilliant and clear jelly and -a further object of this invention is to produce such a pectin product without any substantlalreduction in the natural high jellifying powers of the pectin.

This invention comprehends that while citrus fruit or the other pectin containing organic matter is in the natural state the enzyme pectinase or other enzymes are by the nature of the substances kept essentially separate from the pectin and if these enzymes are destroyedprior to the extraction of the pectin or promptly upon extraction of the pectin, the enzymes will be prevented from coming into contact with the pectin and producing any substantial deterioration of the same, and thus the'formation of pectinic acid and other undesir- .able products ofthe pectin from this cause ing the pectin from the organic matter an- 'pec excizptionally effective extraction of the in may be obtained while still mamtainin the decomposition of the pectin at a. minimum and the employment of th s acid in place of the highly ionized inorganic acids or organic acids heretofore employed will result in a more efiicient extraction and a purer product than has heretofore been obtainable.

This invention further comprehends thatwhen preparing a pectin product from lemons, oranges, or similar citrus fruits a large quantity of those materials which normally form suspended solids and certain milky liquids in the extract may be removed by washing the pul before the extraction of the pectin, an, if this washing is conducted at a tem erature sufiiciently low to prevent materia. decomposition of the pectin and in a relatively short period of time, a superior pectin product may be obtained, which productwill not only produce a clear and brilliant jelly but will maintain the high original jellifying powers of the natural pectin.

This invention further comprehends that when pectin is extracted from organic matter the extract normally contains the pectin in a colloidal solution along with certain materials naturally associated with the pectin in the organic matter, and the pectin can be.

precipitated from such an extract in a purified form by the action of a colloid having an electric charge opposite to the charge. of the colloidal pectin. The pectin thus produced maybe readily freed from the precipitating agent or impurities in the extract and thus a pectin product is obtained whichwill be free fromimpurit'ies and capable of producing a clear brilliant jelly and while maintaining substantially the natural jellifying power. We are aware that it is not new to precipitate pectin from an extract. However, this has ordinarily been accomplished by saturating the extract with certain salts which will cause a salting out of the pectin.

- This is a substantially different manner of precipitating the pectin than the manner disclosed in this invention and produces a substantially different product. Thus when a pectin is precipitated from asaturated solution it naturally includes a great .amount a of the salt or agent employed for salting out the pectin and so far as is known this salt cannot be practically removed.

We have discovered that pectin can be precipitated from itscolloidal solution by a colloidal hydroxide, and this precipitation can be carriedout in dilutesolutions and at a low-temperature, and there will result not only a pectin free from material quantities of a precipitating agent, due to the manner in which it has been precipitated, but also a pectin containing less decomposition products of the pectin, due to the employplied to the preparation of.pectin from the peel of citrus fruits. We desire to be understood to the e'fl'ect that the process de-, scribed is given as an illustration of a preferred example of the invention and the in-,

vention is not to be limited to the preferred example given but the process may be modified in various manners without departing from the spirit of the invention. v

When employing citrus fruit, the peel of the citrus fruit (such as may be obtained from any process for expressin the juices or oil from the fruit), is choppe into pieces ranging from i to 4 inch in size. This chopping of the peel into small pieces isfdone simply to facilitate the extraction of the peetin and is not essential'to the operation of the processor the preparation of the product. i

The peel should then be heated to a temperature suflicient to destroy the enzyme pectinase' in the peel so that when the pectin is extracted these enzymes will not act upon the pectin to decompose same or" to form pectinic acid. This heating should be con ducted with extreme care to prevent overheating. of the pectin which would result in a decomposition thereof. the temperature to which the peel should be heated should not exceed 100 C. and th peel should not be heated substantially more than; ten minutes.

While it is preferable to destroy these enzymes prior to the extraction the enzymes may be destroyed immediately'up'onextraction by a simple heating step, although slilght decomposition ofthe pectin may resu t. After the enzymes have been destroyed it is desirable to, wash the rawmaterial with water to remove the majority of those substances which if permitted to pass into the pectin extract would form fine suspended solids and milky liquids. While this washing will extract a small amount of pectin the removal of the undesired impurities as well as a large number of any of theproducts between pectin and pectinic acid resent .will far offset this loss of pectin. T e washing of the raw material is carried out-with water which shouldnot be heated to its boiling tween 80 and 90 C.

point. The washing process should not be unduly repeated on account ofthe loss of pectin and for the reason that pectin should not be exposed to high temperature any longer than is necessary in the process.

The pectin is then extracted from the washed and purified peel by the use of an acidified water which is preferably not heat- I ed to a temperature over 100 C. The extraction may consist of a number of extraction steps, stepping up the extraction to give a concentrated pectin extract or the extraction may be conducted in one step by the use of a large volume of the acidified water. lVe find it preferable to employ a s1ngle extraction to lessen the handling of the pulp and exposure thereof to the high tempera ture. Six to eight volumes of acidified water to every volume of pulp employed Wlll ive an eflicient extraction. In general the gest results are obtained when the temperature of the acidified water is maintained be- Inorganic acids and some organicacids may be used in this extractionoperation but we have determined that the employment of sulphurous acid will result in a materially more satisfactory extraction of pectin and less decomposition of the pectin during the extraction period than any-other acld or agent so faresmployed. This acid should be employed for the best res'ultsin concentrations from it to 1%. The extract so obtained contains pectin in colloidal form and the solution may alsocontain small amounts of fine suspended solids and milky liquids not removed by the prior washing step and the extract will appear slightly opalescent or cloudy. The entrained matter and part of such, suspended solids may be removed by centrifugal apparatus. 'VVe have found the addition of paper pulp to the extract followed by filtration through a filter will remove a substantial quantity of such impurities and also that a substantial quantity of the same may 'be filtered out upon'the pulp from which the extract is formed by care-' fully drawing off the extract through the same. I

The clarified solution may then be concentratcd or dried to obtain the pectin. However. in such a case, the concentration and drying-of the pectin will result in somedecomposition of the pectin with a loss in jellifying powers and the concentrated or dried product will contain certain impurities orvegetable matter naturally associated with the pectin, which will be imparted to the jelly or other material produced by the pectin and the clearest and most brilliant jelly cannot be obtained. We have found that materially less decomposition of the.

pectin-will occur and a pectin product conthe solution is dilute and at alow temperature. While various colloids may he employed to accomplish this precipitation,providlng thecolloid is oppositely charged to the colloid of the pectin, we find the employment of colloidal hydroxides to be preferable. This colloidal. hydroxide may be introduced-into the colloidal pectin extract in the following manners.

' The extract is first made slightly alkaline with a solution of a weak alkali, ammonia being preferred for this purpose. A metallic salt is then added, which in the presence of the weak alkali (ammonia) will form a colloidal hydroxide. The quantity of metallic salt added should be such that the resultant action with the pectin extract and ammonia or weak alkali will neutralize or render the solution very slightly acidic. As a metallic salt we prefer to employ either magnesium sulphate,;alum or aluminum sulphate. aluminum sulphate having been quantities of the actual pectin solution to be treated. To different examples of the pectin extract are added different quantities of the weak base and metallic salt and the sample giving the best amount and quality of the precipitated pectin indicates the correct proportions to be employed. A slightexcess of the metallic salt or'aluminum sulphate will furnish the desired electrolyte for the solution. It is also'possible to prepare thealuminum hydroxide and apply it instead of forming'aluminum hydroxide in the extract.

Such aluminum hydroxide is the active precipitating agent of the process being a colloidal hydroxide of an opposite charge to the charge of the colloidal pectin. On addition of such colloidal hydroxide the pectin will then be precipitated from the extract. It is generally foundthat slightly more of the metallic salt is required than the mass of pectin which will be found in the solution. A colloidal hydroxide such as aluminum hydroxide may also be supplied .by adding to the extract a salt which is highly dissociated by water and forms after dissociation a colloidal hydroxide. Alumi-' num acetate is an example. of such a salt.

materials forming suspended solids or milky liquids. and will roducea clean-brilliant jelly. The precipitated pectin may be-sep-'- arated from the solution by any one of a number of filtering devices or by centrifugalapparatus, or the mother liqucr may be decanted ofl. We have found the separation may be most readily accomplished if the solution is aerated by some suitable method' such as injecting into thjei solution-a fine spray of air or by running a streamof the solution on to a revolving disk. The areation of-the. solution serves to attach minute Y air bubbles to the ectin and cause the pectin; to separate from the mother liquor and r se tothe topof the liquor forming aj compact scum. I

After'the separation of the pectin from the-mother liquor the pectin is then washed with water until it is free of the soluble salt. There being but a slight excess of the soluble salt 'in the extractfonly a slight precipitated with the amount ofsalt is pectin and this washing may readily be accomplished. Thewashing is best accomplished by agitating the precipitate with the wash water,;allowing the mass to. stand, and drawing of? the wash water from the precipitate. The washed pectin contains a large amount of water. .Th1s water is dif-i ficult to separate by common forms of filtering apparatus but can be removed; in contrifugal machines. We find, however, that the/most satisfactory results are laccomplish'ed'by .the use of a hydraulic .press. The ,pectin isthen dried in a suitable apparatus wherein, it should not be heated over -100'C;..and the drying should be accom.-

plished ii the. shortest time necessary to remove anteater. Vacuum. or air drlers may be used or' a-fspray dryingmachine,

, of an amount sufiicientto neutralize the h finepowder after which itis ready for use. The dried product with alcohol containing ihydro-. chloric acid. The amount of hydrochloric acid employed should be slightly in excess droxide inthepectin. In this manner t e' hydroxide is converted into aluminum chloride which is soluble in the alcohol. The pectin is then separated from the alcohol solution and may bewashed with fresh alcohol to remove traces of the aluminum chloride and excesshydrochloric acid. This furtherffree from the roductwill contain --a slight amount of a uminumhydroxide. 'We have? discovered that'this may be readily removed from the product by washing the dried the alcohol dissolves. the natural coloring matter in the pectin product and roduces a pectin which maybe used in making jelly or similar productswithout imparting any color to the same. By the use of this washing the pectin product is'freed from substantially all mineral matterand other inipurities'and the pectin in the product still I in quality to the'pectins normally roduced and therefore we desire to claim )Oth-the improvements in'the process for producing the (pectin and theimproved form ofpectin pro not provided by such process. The invention isof thefscope set forth in the acanying claims.

comp T l's'application is a continuation in part of our'application Serial No. 571,536. filed June 28, 1922.

We claim: v r

1. A dry pectinproduct containing pectin which retains substantially unimpaired all of the natural high jellifying powers of the pectin in the raw material, said pectin being substantially free of the impurities naturally occurring in a pectin extract, by virtue ofp'reclpitating the pectin from the extract by means of colloidal hydroxide having a charge opposite tow the charge of the pectin 'in the extract., I I 2. A pectin product substantially free of natural impurities such as color, flavor andmineral ash through precipitating the pectin j :from an extract of the natural material'by the action of a colloid having a charge opposite to the charge of the pectin whereby the impurities of the extract are separated from A v the peotinwithout'destruction of the jellify- The pectin" should then ground to a ing powers of thesame, said. product being precipitating. agent by "removing the same with alcohol and hydr'ochloricacid.

3. A process of producing ectin,' wh ich includes forming an extract .0 pectin from organic matter by treating the organic mat-j 'ter'with'an acid solution, and precipitating the pectin'from the extract by the action of an oppositelycharged colloid. i 4..A process of producing pectin, which includes forming an extract of pectin from organic matter by treating the organic. matterwith an acid solution, and precipitating the 'ectin from the extract by the action of a co loidal hydroxide having a charge oppo site to that ofthe colloidal pectin.

.reagent, has the additional advantage that' 5. 'A process of producing pectin, which, J30 l includes runnin ail-extract of pectin from organic matter, and precipitating the pectin from the extract by the action of a. colloidal hydroxide having an opposite charge from the colloidal pectin. v

6. A process of producing pectin, which includes forming an extract of pectin by treating organic matter with an acid solu-' tion, and adding a weak alkali and a me-' tallic salt to the extract, the metal of the which the pectin containing v imaterial is heated prior to the extraction of the pectin to destroy the enzyme pectinase invthe material, and the pectin is then extracted.

9. The process of producing pectin which includesrextracting pectin from organic material by means of sulphurous acid. Y

10. The process of producing pectin which includes extracting pectin from organic matter by means of a solution of sulphurous acid, and adding ammonia and an aluminum salt to the extract insuch proportions that colloidal aluminum 'hydroxlde is formed in' the presence of an excess of thealuminum salt such excess of the aluminum salt making the reaction of the solution after precipitation" neutral or very slightly acid.

11. A process of precipltating pectin, in

which an extract of pectin is treated with a colloidal hydroxide in presence of anelectrolyte, whereby the pectin is precipitated.

ter by treating the organic matter with a sulphurous acid solution, and precipitating the pectin from the extractby the action of a colloidal hydroxide having a charge opposite to that of the colloidal pectin.

13. A process of producing'pectin, which includes extracting pectin from organic matter by treatingthe organic matter with an acid solution, and introducing va colloidal hydroxide having a chargeopposite to that 12. A process of-producing pectin, which mcludes extracting pectin from organic mat;

of the coloidal pectin and anelectrolyte having a metal in common with the'coloidal hydroxide, thereby precipitating the pectin.

14. The process of producing pectin which includes extracting pectin from citrus material by treating the citrus material with a sulphurous acid solution'having a concentration of i to 1%, precipitating the colloidal pectin from the extract'by introducing .a colloidal aluminum hydroxide into the extract and a slight amount ofsoluble aluminum salt, removing the precipitated pectin from the liquor, drying the pectin, neutralizing" the aluminum hydroxide in the product with a solution of a suitable acidin alcohol,

and washing the dried product until it is substantially free from the aluminum salt present,

Signed at Corona, Cal. 14 day v0t August; 1923.

ELoisE JAMESON. runners N. TAYLOR. OLABENGE P. WILSON. 

